at this school outside boston, an extreme example, was entirely legal. >> some day we are all going to look back and we're going to say, can you believe what we did here? >> reporter: an abc news investigation has found that only 17 states have specific laws protecting students from harsh treatments and restraints. >> that's there's thousands and thousands of children that have been traumatized, that have been injured. >> reporter: in arizona and washington state, parents are up in arms over padded isolation boxes or cells where students have been left for long stretches. in kentucky a mother found her autistic eight-year-old son had been stuffed into a duffel bag like this one, especially made to restrain children. >> they held me. >> reporter: in pennsylvania a group of students with behavioral issues described to abc news how they had been tied up or manhandled at previous schools. did it hurt? >> yeah. it really did hurt. >> reporter: jordan described being locked up in one of the isolation boxes? >> it's scary. really scary. even for the bravest person in the world, it's still really scary.